#include "Arduino.h"

int led[3] = {11, 10, 9};
int cnt = 0;

// the setup routine runs once when you press reset:
void setup() {
  // initialize serial communication at 115200 bits per second:
  Serial.begin(921600);
  for (int i = 0; i < 3; i++)
  {
    pinMode(led[i], OUTPUT);
    digitalWrite(led[i], 1);
  }
}

// the loop routine runs over and over again forever:
void loop() {
  for (int i = 0; i < 3; i++)
  {
    digitalWrite(led[i], 0);
    delay(500);
    digitalWrite(led[i], 1);
    delay(500);
  }
  cnt++;
  Serial.print("toggle count: ");
  Serial.println(cnt);
}
